Researchers have identified a gene in mice capable of producing an innate antiviral response to infection. Their findings appear in the November 2005 issue of the Journal of Virology.

The innate immune response, largely composed of the alpha/beta interferon system, is the first defense against controlling viral infections. These interferons are produced in response to viral infection and stimulate specific genes to produce antiviral compounds. These interferon-stimulated genes (ISGs) are responsible for many of the bodies' innate antiviral activities, but there are still some effects yet to be explained by the genes already identified.

In the study researchers used a modified Sindbis virus to express selected ISG responses in mice and looked for an attenuated infection. Through this approach they identified the interferon-stimulated gene 15 (ISG15) as having antiviral activity, protecting mice against mortality and decreasing viral replication in multiple organs.

"We show that expression of ISG15 in INF-á/âR mice attenuates Sindbis virus infection, providing in vivo evidence that ISG15 can function as an antiviral molecule," say the researchers.